Urs Wiedemann (CERN):

A theorist's look at first data from the LHC heavy ion programme

Abstract:

This talk will focus on two central and exemplary features seen in the data from the first LHC heavy ion run at √(s_NN) = 2.76 TeV. First, data on soft particle production that characterize the bulk properties of the medium created in the collision, show imprints of strong collectivity. Second, essentially all 'hard' high-momentum transfer processes with hadronic final states are strongly modified in nucleus-nucleus collisions, if compared with the corresponding yields and distributions in proton-proton collisions. I shall discuss in detail achievements and deficiencies of the theory with which these data are understood, how LHC has advanced already now our understanding of nucleus-nucleus collisions, and which novel questions are now coming into reach.